jsimple.util

Class HashSet<E>

java.lang.Object

jsimple.lang.Iterable<E>

jsimple.util.Collection<E>

jsimple.util.Set<E>

jsimple.util.HashSet<E>

All Implemented Interfaces:

java.lang.Iterable<E>

public class HashSet<E>
extends Set<E>

HashSet is an implementation of a Set. All optional operations (adding and removing) are supported. The elements can be any objects.

Changes from the java.util version:

Does not support clone; use HashMap constructor taking a Collection argument instead (which is more flexible and type safe)

Constructor Summary

Constructors

Constructor and Description
HashSet() Constructs a new empty instance of HashSet.
HashSet(Collection<E> collection) Constructs a new instance of HashSet containing the unique elements in the specified collection.
HashSet(E... args) Constructs a HashSet, with the specified initial members.
HashSet(int capacity) Constructs a new instance of HashSet with the specified capacity.
HashSet(int capacity, float loadFactor) Constructs a new instance of HashSet with the specified capacity and load factor.

Method Summary

Modifier and Type	Method and Description
boolean	add(E object) Adds the specified object to this HashSet if not already present.
void	clear() Removes all elements from this HashSet, leaving it empty.
boolean	contains(E object) Searches this HashSet for the specified object.
boolean	isEmpty() Returns true if this HashSet has no elements, false otherwise.
Iterator<E>	iterator() Returns an Iterator on the elements of this HashSet.
boolean	remove(E object) Removes the specified object from this HashSet.
int	size() Returns the number of elements in this HashSet.

Methods inherited from class jsimple.util.Set

equals, hashCode, removeAll

Methods inherited from class jsimple.util.Collection

addAll, containsAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

HashSet

public HashSet()

Constructs a new empty instance of HashSet.

HashSet

public HashSet(int capacity)

Constructs a new instance of HashSet with the specified capacity.

Parameters:

capacity - the initial capacity of this HashSet.

HashSet

public HashSet(int capacity,
               float loadFactor)

Constructs a new instance of HashSet with the specified capacity and load factor.

Parameters:

capacity - the initial capacity.

loadFactor - the initial load factor.

HashSet

public HashSet(Collection<E> collection)

Constructs a new instance of HashSet containing the unique elements in the specified collection. Changes from the java.util version: The constructor there supported covariance, taking a Collection<? extends E> argument where the collection can be of a subclass of E. This constructor only allows collections of exact type E, but you can use the addAll method instead if you really need to copy a collection of a subclass.

Parameters:

collection - the collection of elements to add

HashSet

public HashSet(E... args)

Constructs a HashSet, with the specified initial members. Changes from the java.util version: The constructor is new, added as a convenience method to easily create initialized sets.

Parameters:

args - elements to add initially to the set

Method Detail

add

public boolean add(E object)

Adds the specified object to this HashSet if not already present.

Overrides:

add in class Collection<E>

Parameters:

object - the object to add.

Returns:

true when this HashSet did not already contain the object, false otherwise

clear

public void clear()

Removes all elements from this HashSet, leaving it empty.

Overrides:

clear in class Collection<E>

See Also:

isEmpty(), size()

contains

public boolean contains(E object)

Searches this HashSet for the specified object.

Overrides:

contains in class Collection<E>

Parameters:

object - the object to search for.

Returns:

true if object is an element of this HashSet, false otherwise.

isEmpty

public boolean isEmpty()

Returns true if this HashSet has no elements, false otherwise.

Overrides:

isEmpty in class Collection<E>

Returns:

true if this HashSet has no elements, false otherwise.

See Also:

size()

iterator

public Iterator<E> iterator()

Returns an Iterator on the elements of this HashSet.

Specified by:

iterator in interface java.lang.Iterable<E>

Specified by:

iterator in class Collection<E>

Returns:

an Iterator on the elements of this HashSet.

See Also:

Iterator

remove

public boolean remove(E object)

Removes the specified object from this HashSet.

Overrides:

remove in class Collection<E>

Parameters:

object - the object to remove.

Returns:

true if the object was removed, false otherwise.

size

public int size()

Returns the number of elements in this HashSet.

Specified by:

size in class Collection<E>

Returns:

the number of elements in this HashSet.